Today was all systems neuroscience, an area that I don’t quite get. And because of this lack of understanding, research in this field usually falls into two categories to me: questions too simple to study, and questions too lofty to grasp. But still, I found most of the talks interesting and well-presented. Topics range from visual reflex, motor coordination and learning, to reward and decision making.
The one talk that I really like is a functional imaging study of conditioned fear memory from the Schnitzer lab. The presentation was too fast to absorb every bits of detail and the computation is little too difficult for me, but the gist of it is that they managed to perform calcium imaging in an ensemble of neurons in lateral amygdala, an area critically important for the formation, storage and retrieval of fear memory, during a typical conditioned fear memory paradigm. The take home is that during training sessions, the populational activity pattern of neurons responsive to the conditioned stimulus (CS) becomes more similar to the neurons responsive to the unconditioned stimulus (US); and this similarity becomes even higher during the consolidation period after the training. What’s more interesting is that after memory extinction, the similarity between the CS and US neurons is lost, but the activity pattern of the CS neurons do not reverse back to their naive state before training, rather they adopt a totally different state, which suggests that extinction is perhaps not a simple erasure of the established memory but is an active mechanism driving the cells into a new circuit.